The present invention relates generally to surgical instruments and, more particularly, to a handle mechanism for surgical instruments used in ophthalmic surgery such as forceps, scissors and other instruments having a surgical device that includes tips which move in response to the movement of the handle mechanism.
In one such instrument the surgical device is a pair of spring steel segments inserted into a guide tube attached to a handle. Each spring steel segment has a constant cross sectional dimension and is identical in dimension to the mating spring steel segment. For the purposes of this description, the spring steel segment assembly will be referred to as having a left hand and a right hand segment which are mirror images of each other. Each segment has an inner and an outer surface and, when assembled, the inner surfaces abut one another. The steel segments are manufactured to have a spring bias such that when the segments are unrestrained they curve away from each other.
At the distal end of each spring steel segment a tip is formed, shaped as a tool to carry out an action useful in surgery, such as gripping or cutting.
The handle includes a carriage to which the guide tube is attached. The carriage is movable axially within the handle responsive to the actuation of a leaf-type handle mechanism. As the tube is extended from the handle the tube contacts the biased-apart spring steel segments and the tips are forced towards one another. Such instruments are capable of performing different surgical tasks depending upon the design of the tool formed at the tips. For example, the tips can be formed as a pair of jaws useful as a forceps, with the jaws alternately grasping and releasing tissue as the handle mechanism is operated. The tips can also be formed as a pair of scissor blades which, when reciprocated by the handle mechanism can be used to cut tissue. The motion of the tips will continue so long as the handle mechanism is operated.